Sn=n/2 (2a1 +(n-1)d)
[s5= 5/2 (2a1 +(5-1)d) = 5a1+10d]
s6=3(2a1+5d) = 6a1+15d
s4=2(2a1+3d) = 4a1+6d
6a1+15d -(4a1+6d) = 5 -----(1)
s7=7/2(2a1+6d) =7a1+21d
6a1+15d + 7a1+21d = 21 -----(2)
(1) 2a1+9d=5 -----(3)
(2) 13a1+36d=21 ----(4)
(3)*4 ; 8a1+36d=20 ----(5)
(4)-(5) 5a1 = 1
so a1 = 1/5
(3) 2a1+9d=5
2(1/5)+9d = 5
9d = 5-2/5 =23/5
d = 23/45
so [s5= 5/2 (2a1 +(5-1)d) = 5a1+10d = 5(1/5) + 10(23/45) = 1 + 5.11 = 6.11 ]
i'm not sure about the answer but the process is correct
Answer:
The unit circle is a circle with a radius of 1.
This means that for any straight line drawn from the center point of the circle to any point along the edge of the circle, the length of that line will always equal 1
Step-by-step explanation:
13 miles per gallon....13/1
now all u have to do is find an equivalent fraction.
26/2 = 13/1...they're equivalent...so ur answer is 26/2
Answer: $29.70
Step-by-step explanation:
250 times the annual interest (12%) is converted to 250 times .12 = 29.70
If the car travels at the same speed for 12 hours the total miles will be 680.4
